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arXiv · 1906.11627

Bulk single crystal growth of the theoretically predicted magnetic Weyl semimetals $R$AlGe ($R$ = Pr, Ce)

P. Puphal·C. Mielke·N. Kumar·Y. Soh·T. Shang·M. Medarde·J. S. White·E. Pomjakushina
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Abstract

We explore two methods for single crystal growth of the theoretically proposed magnetic Weyl semimetals $R$AlGe ($R$ = Pr,Ce), which prove that a floating zone technique, being both crucible- and flux-free, is crucial to obtain perfectly stoichiometric $R$AlGe crystals. In contrast, the crystals grown by a flux growth technique tend to be Al-rich. We further present both structural and elemental analysis, along with bulk magnetization and electrical resistivity data on the crystals prepared by the floating zone technique. Both systems with the intended 1:1:1 stoichiometry crystallize in the anticipated polar I4$_{1}$md (No. 109) space group, although neither displays the theoretically expected ferromagnetic ground state. Instead PrAlGe displays a spin-glass-like transition below 16 K with an easy-c-axis and CeAlGe has an easy-ab-plane antiferromagnetic order below 5 K. The grown crystals provide an ideal platform for microscopic studies of the magnetic field-tunable correlation physics involving magnetism and topological Weyl nodes.

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P. Puphal, C. Mielke, N. Kumar, Y. Soh, T. Shang, M. Medarde, J. S. White, E. Pomjakushina. 2019-06-27. Bulk single crystal growth of the theoretically predicted magnetic Weyl semimetals $R$AlGe ($R$ = Pr, Ce). https://doi.org/10.1103/physrevmaterials.3.024204

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